<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://unpkg.com/vue"></script>
</head>
<body>
<div id="example">
    <p>Original message:"{{message}}"</p>
    <p>Computed reversed message:"{{reverseMessage}}"</p>
</div>
<script>
  var vm=new Vue({
      el:'#example',
      data:{
          message:'Hello'
      },
      computed:{
          reverseMessage:function(){
              return this.message.split('').reverse().join('')
              console.log(vm.reverseMessage)
          }
      }
  })

</script>
</body>
</html>